data connection_error ai_generated true

IOException: Could not connect to NameNode

ID: data/hdfs-namenode-unavailable

Also available as: JSON · Markdown
78%Fix Rate
82%Confidence
3Evidence
2023-01-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
any active — — —

Root Cause

HDFS NameNode not reachable.

generic

Workarounds

  1. 88% success Check NameNode process and JVM heap: jps and logs
  2. 90% success Use HA NameNode with automatic failover (ZooKeeper)

Dead Ends

Common approaches that don't work:

  1. Kill and restart NameNode without safe mode 85% fail

    Potential metadata corruption

  2. Switch to secondary NameNode as primary 88% fail

    SecondaryNN is for checkpointing not failover